13,966 research outputs found
Photon plus heavy quark production in high energy collisions within the target rest frame formalism
We apply the target rest frame formalism to photon + heavy quark production
cross section in hadronic collisions at high energies. We investigate the
dependence of the production cross section on the photon and quark rapidities
and transverse momenta. It is shown that the photon transverse momentum
spectrum is a sensitive probe of color dipole scattering amplitude. The
theoretical results are compared to Tevatron measurements of the differential
\gamma + c + X and \gamma + b + X production cross sections at 1.96 TeV. An
analysis for proton-proton and proton-lead collisions at the LHC regime is also
performed.Comment: 6 pages, 3 figures. Version to be published in Physical Review
Geometric scaling in ultrahigh energy neutrinos and nonlinear perturbative QCD
The ultrahigh energy neutrino cross section is a crucial ingredient in the
calculation of the event rate in high energy neutrino telescopes. Currently
there are several approaches which predict different behaviors for its
magnitude for ultrahigh energies. In this contribution is presented a summary
of current predictions based on the non-linear QCD evolution equations, the
so-called perturbative saturation physics. In particular, predictions are shown
based on the parton saturation approaches and the consequences of geometric
scaling property at high energies are discussed. The scaling property allows an
analytical computation of the neutrino scattering on nucleon/nucleus at high
energies, providing a theoretical parameterization.Comment: 6 pages, one figure. Presented at First Caribbean Symposium on
Nuclear and Astroparticle Physics - STARS2011, La Habana, Cuba, 2011. arXiv
admin note: substantial text overlap with arXiv:1011.2718 by different
author
Geometric scaling in ultrahigh energy neutrinos and nonlinear perturbative QCD
It is shown that in ultrahigh energy inelastic neutrino-nucleon(nucleus)
scattering the cross sections for the boson-hadron(nucleus) reactions should
exhibit geometric scaling on the single variable tau_A =Q2/Q2_{sat,A}. The
dependence on energy and atomic number of the charged/neutral current cross
sections are encoded in the saturation momentum Q_{sat,A}. This fact allows an
analytical computation of the neutrino scattering on nucleon/nucleus at high
energies, providing a theoretical parameterization based on the scaling
property.Comment: 5 pages, 4 figure
Intrinsic versus super-rough anomalous scaling in spontaneous imbibition
We study spontaneous imbibition using a phase field model in a two
dimensional system with a dichotomic quenched noise. By imposing a constant
pressure at the origin, we study the case when the interface
advances at low velocities, obtaining the scaling exponents ,
and within the intrinsic
anomalous scaling scenario. These results are in quite good agreement with
experimental data recently published. Likewise, when we increase the interface
velocity, the resulting scaling exponents are , and . Moreover, we observe that the local
properties of the interface change from a super-rough to an intrinsic anomalous
description when the contrast between the two values of the dichotomic noise is
increased. From a linearized interface equation we can compute analytically the
global scaling exponents which are comparable to the numerical results,
introducing some properties of the quenched noise.Comment: Accepted for publication in Physical Review
Influence of Disorder Strength on Phase Field Models of Interfacial Growth
We study the influence of disorder strength on the interface roughening
process in a phase-field model with locally conserved dynamics. We consider two
cases where the mobility coefficient multiplying the locally conserved current
is either constant throughout the system (the two-sided model) or becomes zero
in the phase into which the interface advances (one-sided model). In the limit
of weak disorder, both models are completely equivalent and can reproduce the
physical process of a fluid diffusively invading a porous media, where
super-rough scaling of the interface fluctuations occurs. On the other hand,
increasing disorder causes the scaling properties to change to intrinsic
anomalous scaling. In the limit of strong disorder this behavior prevails for
the one-sided model, whereas for the two-sided case, nucleation of domains in
front of the invading front are observed.Comment: Accepted for publication in PR
Parton saturation effects to the Drell-Yan process in the color dipole picture
We report on the results obtained in the study of the parton saturation
effects, taken into account through the multiscattering Glauber-Mueller
approach, applied to the Drell-Yan (DY) process described in the color dipole
picture. As a main result, one shows that those effects play an important role
in the estimates of the DY differential cross section atRHIC energies.Comment: To appear in the proceedings of the VIII International Workshop on
Hadron Physics 200
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